Submarine signaling.



2 SHEETS-SHEET I.

Pat-ented Sept. 7, 1915.

NYETUB Di flam 87 %712% I TTUH'EY.

APPLICATION FILED MAY22.1909.

T. BODDE.

SUBMARINE SIGNALING.

APPLICATION FlLED MAY22,1909.

1,152,697. PatentedSept. 7, 1915,

2 SHEETS-SHEET 2.

WI 53858: f /IVEIITOR PTE SUBMARINE SIGNALIN G.

risaeaa To all whom it may concem:

Be it known that I, TIIEODORE Bomm, a subject of the Queen of Holland,residing in Brant Rock, in the county of Plymouth, in the State ofMassachusetts, have invented a certain new and useful Improvement inSubmarine Signaling, of which the following is a true and exactdescription, reference being had to the accompanying drawings, whichform a part thereof.

The present invention relates to the transmission of audible signalsthrough water. It is well known that the method of Signaling by means ofsound waves transmitted through the water has certain importantadvantages in marine work, over signaling by means of lights or by meansof sound waves transmitted through the air. Signaling by means of lightsis highly effective in clear weather, but is totally inefl ective incloudy or foggy weather, and signaling by means of sound wavestransmitted through the air is inefi'ective and highly unreliable,particularly during cloudy or foggy weather. The changes in density ofair produced by the wind, and also by clouds and fog, make it difficultto determine the direction from which the sound originates when it isheard at all, and makes the distance from the point of transmission atwhich the sound may be hearda very uncertain and variable quantity. Thedensity of the water, on the other hand, is not materially affected bythe weather or the motion of the water, and, in consequence, thedistance from the point of transmission at which sgnals may be heardthrough the water remains practically constant, and by making suitableprovisions at the receiving station, the direction from which the soundcomes through the water can be determined with substantial accuracy. Forinstance, in the case of ships it has been found entirely feasible todetermine the general direction from which the sound transmitted throughthe water is received by providing two telephonic receiving devices,each secured to the hull of the ship below the water line and arrangedone on the port side and the other on the starboard side of the ship.The difference in intensity of the sound heard at the two receivingdistances enablesthe direction of the source of sound to be determinedwith fair accuracy.

Heretofore, so far as I am aware, the only 5 device employed forgenerating sound waves Specificaton of Letters Patent.

Application filed May 22, 1909.

Patented Sept. '7, 1915.

Serial No. 4973592.

traveling through the water which has been used in practice is thesubmerged bell and strker, the striker being actuated by an electricmotor, compressed air motor, Wave motor, or other suitable device.

One object of the present invention is to provide a method of, andapparatus for, generating sound waves in Water which will travel fartherthan those which it is practical to produce With the submerged bell andstrker, and which give a control of the fre quency or pitch of the soundwaves not practcally possible with the bell and striker.

A further object of the invention is the provson of sound wavegenerating apparatus which, on account of its relatively small bulk andthe manner in which it may be mounted on a ship, can be much moreConveniently and eifectively arranged and supported on the ship than canthe usual submerged bell. In the present use of audible submarinesignals, the sound producing bell used on a ship is hung over the sideof the ship and is not easy to manipulate, especially When the ship isin motion.

' In carrying out my invention,--and broadly speaking, the essence of myinvention consists in this,-I cause an intermittent flow of electricityof a character to produce disturbances in the surrounding medium tooccur under such circumstances that the impulses of electrical currentoperate directly to set the water into vibration with the desiredfrequency and amplitude of vibration for the transmission of sound ofthe desired pitch and intensity through the water.

The apparatus which I may use for the purpose may be of many differentforms and in the accompanying drawings and descriptive matter I haveillustrated and described several of these forms.

It will be apparent to those skilled in the art, however, that theinvention in its broader forms may be embodied in, or carried out by,other apparatus than that disclosed, although the invention in itsnarrower aspects consists in part in certain features of combination andarrangement peculiar to the apparatus shown and described.

Of the drawings, Figure 1 is a diagrammatic elevation of a portion of aship equipped with one form of my new signal sending apparatus. Fig. 2is a sectional ele- Vatien electricah sound wave generating deviceempleyed in the arrangement shown in Fig. l. Figs. 3, e, 5 and 6 areeach taken similarly to Fig. 2 and each shows a Construction differingin some respects from.

that of each of the other figures of this group. Fig. 7 is adiagrammatic elevation, partly in section, illustrating a sound waverefiector tor causing sound waves to be concentrated and sent in onedirection. Fg. 8 is a View similar to Fig, l, illustrating currentsupply connections, different from those in lFig. l ernployed inconjunction with the transmtter shown in Fig. 3. Fgs. 9, 10 and ll areeach taken siniilarly to Figs. l and 8 and each illustrate circuitconneetions difi'ering from those shown in Figs. 1 and 8 the particulartransmitters shown in Figs. 9, 10 and 11 being the same as those shownin Figs. 4 5 and 6 respectively. Fig. 12 is a diagrammatic View, p'artlyin section illustrating another form of wave generator and circuitconnections.

in the drawings, and referring first to the Construction shown in Figs.l and 2, A represents the wall or skin or" a Vessel, and X the surfaceof the water in which the vessel floats. C is an electrode in the :torrnof a bushing passing through an opening forrned in the hull wall A, andSecured in place by means a collar or fiange C' on the outer end of thehushing C, and a nut screwed on the inner threaded end of the hushing C.Of course it will be understood that the collar C and nutE rnay haveclamped between them either a partition of the regular hull wall of theship or a portion of a plate or other special wall portion. D is ahushing of insulating material having an enlarged and rounded head D' atits euter end which hears against the fiange C' and represents aconductor or electrode centrally disposed in the hushing D, and providedat its outer end with a small enlargenent or sparking knoh in Fig., l"the conductor B and the hushing C are shown connected to the brushes GG' of an alternating current generator G. H represents a switch hy meansof which the circuit of the generator may he interrupted. causes a flowof a-lternating current to take place between the knob B' and the enterer;- posed end of the tlange C" and with each current impulse that isfor each half wave of the alternating current flow produced hy thegenerator G some ef the water surrounding the small lrnoh B isVape-rite& and the water medium between the lrnoh B* and celiar C issuhjected to a pcwerful strain, *aus creating a powerful 'wave inipulseLi the water., by regulating the freerater Gr, the frequency the wavepulses aparted te the wa er in which. t

queney of the current supplied by the genshite cats he 'te roduce a:hust- The generator G' cal tone at the receiving device of the mostfavor-able pitch for detecting sound at a considerable distance, forinstance the frequeney or" the sound waves in the water nay well rangebetween five hundred and one thousand 'per second. By manipulatingswitch H to open and close the energizing circuit intelligible signalwaves may' be transnitted. `With the sending device of l igs.- l and 2,moreover, the source of current may be a direct current source .tor ifthe circuit has sufiicient inductance the de- Vice will operatesatisfactorily as a l/Vehnelt interrupter to produce a pulsating currentof the proper frequency. I

The transmitter shown in Fg. 3 dirs froni that shown in Fig. 2 in thatthe head, or fiange, C' of the electrode bushing C is cnlarged and formsa chamber C surrounding the sparking knob B, the front wall of thischanber being closed by a thin fiexible inetallc daphragm l. The spacewithin the chamber 0 is filled with some non-conducting fluid such asoil or dstilled water. The passage of an ntermittent current ofelectrcity of suitable intensity between the knob B and the wall of thechamber 0 creates powerful disturbances, or surges, in the fluidinclosed in the chamber, and these impulses are transmitted through theflexible diaphragn l to the water in which the det 'ice is submerged.Pipes Y, Y form a means for filling the chamber C and if desired, forobtaining a circulation of the insulating fluid through the chamber. inplace of a liqud such as oil or distilled water, the chamber 0 may befilled with air or other gas, but in such case the deviceis lesseffective than when the filling is a comparatively incompressibleliquid.

in th diagram shown in Fig. 8, in which the transmitter of Fig. 3 isemployed, the circuit connections are slightly difierent from thoseshown inFig. l. in Fig. 8 'the brushes G@ G of the generator G- areconnected to the termin-als of the primary coil of the transmitter, andthe secondary M or the transformer has its terminals connected, one tothe conductor B and the other to the hushing C. A condenser N isconnected across the terminals of the secondary M in Shunt with the gapbetween the electrodes D and C. lt will be understood, however, that thecircuit arrangements of Figs. and 2 can be interchangeably used with thetransmitters of lFigs. 2 and 3.

in the form of the transmitter shown in l, the head D' of the insulatingbushing is enlarged to form a chamherD open at its outer end through arestricted passage this form also the head B of the conductor B, locatedwithin the c` amher Di is a fiat disk or pole of substantial size. W'iththis arrangenent, when a suitable intermttent current flow is maintainedbetween the pole B and the flange C' of the bushing C, the vaporizationoccurring at the exposed end of the pole B will cause powerful j ets tobe forced through the small port D The elect'ic discharge between theexposed electrode portions B and C' takes place in the water in whichthese electrode portions are submerged and passes through the aperture DThe electrodes B and C of Fig. 4: may be connected within the ship toany suitable source of alternating current, as by the means illustratedin Figs. l and 8. With the transmitter shown in Fig. 4, moreover, anintermittent' current flow may be obtained between the submergedelectrodes by connecting them to the terminals of a suitable directcurrent source such as the source O of Fig. 9, for when a suitablereactance P is provided in circuit with the electrodes of thetransmitter and the source of direct current, the device will act as aWehnelt interrupter to make the flow of current a pulsating one.

The transmitter shown in Fig. 5 difl'ers from that shown in Fig. 2 onlyin that the knob B' is connected to the flange C' of the electrode C byone or more filaments K, formed of platinum or like metal, so chosenthat they will be raised to incandescence at each pulsation of currentflow.

In Fig. 10 I have shown the circuit connections for a transmitter, suchas is shown in Fig. 5, which comprise a source of direct current O and arotating commutator Q interrupting the current flow to give thenecessary pu sations.

In the form of transmitter shown in Fig. 6 the bushing C does not serveas an electrode, but merely as a securing device. In this form, twosimilar electrodes B passing through the insulating bushing D areemployed. The electrodes B termnate n small sparking knobs B' facing oneanother.

In Fig. ll I have shown means for supplying alternating current to thetwo electrodes B of Fig. 6 which comprises a transformer, to theterminals of the secondary M of which, the electrodes B are connected.The primary of the transformer M' is connected to a source O of directcurrent, but the circuit includes the movable armature R, in inductiverelation with the coil M', and the stationary contact S whereby thecircuit through the primaryis automatically made and broken with thedesired frequency and th e eonsequent production of an alternatingcurrent in the secondary M It will of course be understood that themeans for producing an alternating or pulsating current flow as shown inF igs. l, 8, 10 and 11 may be interchangeably used.

In the form of the apparatus shown in Fig. 12, the electrode B ismovable and is normally spring held by the spring S and armature leverS' in the position in which it contacts with an extension C of thebushing or electrode C. S represents an electromagnet which whenenergized moves the lever S to draw the electrode B out of contact withthe electrode extension C The electrodes B and C' are connected to thebrushes G' and Gr of an alternator G, and the circuit includes aresstance T. The circuit including the alternator and the electrodesbeing closed, the magnet S is energized, and electrode B thereby movedout of contact with the electrode extension 0 An arc s drawn, the arccurrent having of course the frequency of the alternator G.

In practice I prefer to arrange the apparatus so that the increasedresistance of the arc will cause the are to break before or by the timethe electrode B is given its maximum movement of separation. By openingand closng the circuit of the alternator G at predetermined intervalsintelligible signals may obviously be transmitted. The apparatus of Fig.12 possesses an advantage over the other forms shown in that it may beworked at substantially lower voltages.

In Fig. 7 I have shown a modification of the transmitter shown in Fig. 2in which a parabolic refiector, formed by an extension C of the bushingC, is provided. This reflector surrounds the knob B' and serves todirect the sound waves produced by the use of the transmitter in adirection parallel to the arrows shown.

It will be observed that in all forms of the invention the transmittingdevice is readily attachable to the skin of a vessel or other shell orwall to which it may be desired to secure the transmitter, that thetransmitter is relatively compact and small, and this, of course, is asubstantial advantage particularly where the transmtter is applied toships, since it is not likely on the one hand to be injured by contactwith vessels, dock walls, or the like, and on the other hand does notimpede the movement of the ship to which it is attached. It is apparent,of course, that the frequency of the sound waves produced may be easilyvaried by varying the frequency of alternation or pulsation of theintermittent current flow. This not only permits the pitch of the soundwaves to be brought into the range most favorable for transmission butpermits each sending device to have its own distinctive tone. -ByOperating a circuit closing and breaking device such as the switch H,the usual dot and dash code signal may be transmitted.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is:

1. The method of generating sound waves in water for submarine signalingwhich consists in passing an intermittent electric current through afluid medium and thereby 1 setting up mechanee st'resses in such fiu?.medium and transatng such meehancal st'esses into soun weaves in thewater.

2. A sending devce for submarne signalng adapted te be attached to thehull of e ship below the water line thereof, and eomprsng separate&electrodes anti means whereby when said eectrodes are connected; to esuitable source of electrcal energy a eirrent flow of eleetrcty willtake place between sa eectroces of a character to generate sound weavesin the water.,

3. %ending apparatus fer submarne signalng, cemprsng a pair of submergedelectrodes, means fer causing an intel-mittent flow of electrety betweensact e1eetrodes in the water in which the electrodes are submerged.

sending devee for submarne signahng seeufecl to the well of the shipbelow water line thereef and eomptsng eeetrocles having portens expesectexternally of the ship.

5. A sending devce for submarne signalng comprsng electrodes ami meanswhereby they are secure& to the wall of the ship below the water linethereof with portens of said elect'edes exposed externaly of the ship.,

6. In combnaton with the hull ex" a ship, electrodes passing throughsaid hull below the water line and externally expose, andmeans withinthe ship for subjectng said electrodes to such dferences in electrcpotental that an ntermttent flow of electroty will teke place betweensai& electrodes.,

THEODORE BODDE.

`Wtnesses THOMAS B BLACKMAN, i LAURENCE BLACKMAN.

